Gas filters

ABSTRACT

Air filter structure primarily for the ceilings of clean rooms, the structure being formed from a profiled section which can be bolted to a similar structure and hung from the ceiling or supported from a wall each structure being formed to releasably carry a filter, arrangements being provided for filters of different thicknesses, the structure being such that with the filter in place it makes a dust light unit; arrangements may be made for the structure to carry a lighting unit; the structure when bolted to a similar structure may be hung from the ceiling from a web extending upward from the profile section; the releasing arrangements for the filter comprise a clamp which can be screwed down on filters on either side with the filters bearing against a sealing face on the profiled section.

United States Patent 1 1 Soltis 55/484 Neumann Aug. 7, 1973 GAS FILTERS3,418,915 12/1968 Marble 93 40 DL [75] Inventor: Gerhard Max Neumann,Berlin,

Germany Primary Examiner-Remard Nozick [73] Assignee: Delbag-LuftfilterGesellschaft mit Att0mey watson Cole Gnndle & Watson beschrankterllaituug, Berlin,

Germany 57 ABSTRACT [22] Filed: June 7, 1971 A1r filter structureprimarily for the ceilings of clean PPL 150,298 rooms, the structurebeing formed from a profiled section which can be bolted to a similarstructure and hung 52 us. 01 55/484, 55/504, 98/40 1), the ceilingsupported a each 98/40 DL ture being formed to releasably carry afilter, arrange- 511 1m. (:1 13010 31/00 being Pmvided films differentthick- [58] Field of Search 55/483, 4:14, 502, "ems, the Structure beingsuch that with the 55/507 509; 9 40 D 40 DL place it makes a dust lightunit; arrangements may be made for the structure to carry a lightingunit; the [56] References Cited structure when bolted to a similarstructure may be UNITED STATES PATENTS hung from the ceiling from a webextending upward from the profile section; the releasing arrangementsfor 511:" the filter comprise a clamp which can be screwed down 3380'294/1968 z i i i': 52,475 on filters on either side with the filtersbearing against 3,3601910 1/ 1968 a sealing face on the profiledsection.

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GERHARD MAX NEUMANN WATSON COLE GRINDLE & WATSON ATTORNEYS circuits andsemi-conductors, in the pharmaceutical industry of drugs, or in specialhospital wards. In a known air filter ceiling of this kind, filter cellscontaining substances in suspension, situated beside each other in rows,and locking elements, are fastened on a bearer structure in releasablemanner, this structure having,

openings and bearing surfaces for the individual filter cells, and insealing contact. In this form, the grid or grating like bearer structurefor the filter cells, which has to be tied into the walls of the roombelow the ceiling of the room in one unit, must be made on site bywelding together individual parts, according to the dimensions .of theroom. This assembling operation by welding, which is required at thepoint of installation, represents considerable expenditure and waste oftime. To prevent this expense, a procedure has already been adopted,according to which frames consisting of sectional rails and eachreceiving a filter cell are produced at the works, which are assembledside by side in rows at the point of assembly, by beingfastened tobearer elements secured in the ceiling of the room. The frame of thisknown form of embodiment consists of a section wrought in the manner ofa T-beam, whereof the central limb extending at right angles to theceiling forms a box-like hollow unit, a flat section projecting beyondthe same at both sides being secured on its upper side. The part of thissection or rail which projects towards the inside of the frame acts as abearing surface for the filter cell and is equipped with a sealing facefor this purpose. A clamping element for the filter cell is fastened inthe box-like middle web, which may be swung into and out of the middleweb of the frame profile or section by means of a rotatable threadedspindle, engaging in the sides of the filter cell frame in the outwardlypivoted position. To this end, recesses are milled in the outer face ofthe frame, which are penetrated by the clamping elements upon beingpivoted out of the frame section, thereby pressing the filter cellagainst the support face from below. The need for incorporation ofrecesses is disadvantageous since it imposes the application of a frameof greater wall thickness than customary, since risks of fractureprevail otherwise. The outwardly projectingflanges of the flat sectionof the profile serve the purpose of receiving the individual frames inthe bearer elements; to this end, a suspended bearer unit must bearranged on the ceiling of the room, which forms a grid-like frameextending throughout the length and width of the room, in which thesectional frames which each receive a filter cell, must be arranged insealing manner. These frames again had to be assembled at the point ofinstallation by welding or screwing, so that disadvantageous weldingassembly jobs or relatively costly sealing measures are also needed inthese known forms of embodiment. The frame-like bearer element for theindividual filter cell frames consists of downwardly turned intersectionU- sections or rails, in which connection the outwardly projecting partsof the flat section of two profile frames of the filter cell must beborne in sealing manner on each U-section. Complementary thrust elementsacting from above on the profile frame of the filter cell, are necessaryfor this purpose. Moreover, the individual profile frames of the filtercells must be fastened in absolutely sealed manner on the bearing frame,which imposes the need for additional expenditure and neverthelessresults in the intervention of leaks after a protracted period ofoperation, in view of the unavoidably occuring fatigue of the seals.This known form of embodiment accordingly renders it necessary toperform continual inspection of just these seals between the unwieldyprofile frame of the filter cell on the one hand and the bearing frameon the other hand, the dismantling of the profile frames of the filtercells from the bearing'frame being required if leaks arise owing todeterioration of the sealing strips, since retightening of the seals orjoints is practically impossible. The positioning of the light fittingsbetween the ceiling sections, the unreliable sealing measures, theconsiderable consumption of sections and the numerous screwed jointscomprising angle and U-section profiles as coupling bearers, areunfavourable in respect of performance and cost. Moreover, the threadedspindles cannot be replaced at all or with difiiculty only, in the knownembodiments. Moreover, the material consisting of aluminium is chippedoff by the spindles during upward displacement, which is inadmissablefor a white room.

The present invention consists in structure for holding a gas filtercomprising a frame having a profiled section; which section is providedwith means for attaching it to a wall or ceiling,a web portion formed toprovide a sealing face for a filter cell a web portion extending awayfrom the face to a middle web portion adapted so as to be able to beconnected'to the profile section of an adjacent frame, a lower webportion forming a box portion and a clamping element to clamp the filtercell to the sealing face, the lower web portion being adapted to receiveand hold the clamping element.

The accompanying drawings show forms of embodiment of the invention byway of example, and:

FIG. 1 shows a plan view of a frame made up of the section according tothe invention and receiving a filter cell.

FIG. 1A is a sectional view of the frame taken along line IA-lA of FIG.1

FIG. 2 shows an illustration of two adjacent profiles in section and inexploded view, with the threaded and actuating elements which are to beinserted.

FIG. 3 shows an illustration corresponding to FIG. in the operatingposition.

FIG. 4 shows an illustration corresponding to FIG. for the reception offilter cells of greater thickness.

FIG. 5 shows an illustration corresponding to FIG. with a modifiedbearing element.

FIG. 6 shows an illustration-corresponding to FIG. with a modifiedclamping element.

FIG. 7 shows an illustration corresponding to FIG. with a modifiedclamping element.

FIG. 8 shows an illustration of the fastening to the wall of a room.

FIG. 9 shows a modified illustration corresponding to FIG. 8.

FIG. 10 shows another modified illustration corresponding to FIG. 8.

FIG. 1 shows a frame I for reception of a filter cell. This frame mayhave its dimensions matched to the conventional cross-section sizes ofthe filter cell of 6l X 6I cm, 91.5 X 61 cm and 122 X 61cm, filter cellsof different thickness, for example of 5.4 cm, and 15 cm, may bereceived at will in the frame. The frame consists of four profiledsections joined in airtight manner by mitre welds, which are illustratedin detail in FIGS. 2 to 10.

The profiled section is appropriately produced of hard aluminum by theextrusion process. It has an upper web portion 2 extending at rightangles to the ceiling, having a hole 3 formed in it for suspending thesection',from the extremity of the web portion 2 extends a horizontalweb portion 4 which is directed towards the inside of the frame and actsas a bearing face for the upper edge of the filter cell 23. A downwardlydirected oblique web portion 5 is formed at the lower extremity of theupper web portion 2, which is followed by a middle web portion 6extending at right angles to the ceiling, having a hole 7 in its centralarea. This middle web portion 6 is followed by an outwardly openbox-like lower web portion 8 comprising a horizontal first or upperflange 9, a longer vertical connecting web 10 forming a side for the boxand a horizontal second or lower flange 11. At the upper area of the web10 is situated an intermediate flange 12 which is also outwardlydirected. The outer face of the middle web portion 6 and the extremitiesof the flanges l1 and 12 lie in one plane. In the end faces of theflanges 11 and 12 are provided semi-circular recesses or notches 13. Aslot-like hole 14 is provided in the vertical web 10 of the lower webportion 8.

These frames prefabricated at the factory are assembled into a bearingstructure for the filter cells 23, merely by means of screws. To thisend, two adjacent frames are placed with their profiles against eachother, and screwbolts 36 are inserted through the holes 7 of the middleweb portions 6, by means of which the profiles of two adjacent framesare firmly interconnected. Prior to making the screw connection by meansof the bolt 36, the clamping element 15 is placed on the screw spindle17 which is thereupon inserted between the lower web portions 8 of theadjacent profile sections. The threaded spindle 17 has two nylonbushings 31, which are respectively received between the semicircularnotches 13 of the flanges 11 and 12, to prevent the screw spindle 17from coming into direct contact with the flanges 11, 12 when thethreaded spindle 17 is rotated by means of the cap nut 18 fastened onits projecting extremity, in order to press the filter cell 23 by meansof the clamping element 15 and through the joint 24 into contact withthe web portion 4. After the threaded spindle 17 and the clampingelement 14 have been inserted into the two profiled sections, and afterthe latter have been combined into one unit by means of the screwbolt36, the bearing structure produced in this manner and comprising amultiplicity of frames threadedly engaged with each other side by sideand in rows, is suspended from the ceiling, for such purpose essentiallyoptional bearer elements 34 are fastened on the ceiling, which have aneye 35 at their lower extremity which is inserted between the upper webportions 2, whereupon a connecting bolt 37 is inserted, by means ofwhich the frame structure is held at a distance from the ceiling. Afterthis frame structure has been fastened to the ceiling, the individualfilter cells 23 are inserted into the individual frames, the clampingelement 15 which engages under two filter cells 23 adjacent to eachother and is guided in the slots 14 pressing the filter cells through ajoint 24 against the horizontal webs 4 of the frames, by rotation of thethreaded spindle 17. Upon replacing the filter cells, the clampingelements 15 are released by reverse rotation of the screw spindle, beingarranged to be turned in the wider slots, so that the filter cells 23may be withdrawn and replaced by new cells. Between the cap nut 18 andthe lower nylon bushing 31 is situated a washer 18' or spring(rotatable) which serves the purpose of receiving securing elements 20on which may be placed the perforated panels 22 in order to impart apleasant appearance to the underside of the filter ceiling. The securingelements 20 or the box sections themselves may at the same time alsoserve the purpose of receiving fluorescent light tubes 33'forillumination of the room.

Although bearer elements 34 are not an object of the present inventionthey may be provided in a manner as shown in the drawings; in lieu ofthe bearer rods 34, it is also possible to employ a clamping nut 30 oranchoring rails 28,29 secured in the ceiling, or a supporting chain 38.

The forms of embodiment of FIGS. 2,3 and 7 serve the purpose ofreceiving filter cells of lesser thickness, for example of 5.4 cm.Thicker filter cells 23, for example having a thickness of 15 cm, mayhowever be housed in the same frame. To this end, the spindle 17 has adownwardly projecting threaded extension 19; on the spindle 17 issecured a spacing bushing 32 which locates the bolt 18 in axialdirection and engages under the lower web portions 8. A clamping element16 is threaded on threaded extension 19, the two lower projections ofelement 16 engaging under two adjacent filter cells 23. Upon of thespindle 17 by means of the cap nut 18, the thicker filter cells arepressed in the same manner against the horizontal web portion 25. Thefluorescent light tubes 33 may concomitantly be situated between theclamping element 16 on the box sections; if a perforated panel 22 isemployed, they are arranged downwardly directed on the bearer element21.

For the sealing of the bearer structure formed by the frames which arebolted together, it is merely necessaryafter the frames have been boltedtogetherto squeeze a flowable self-curing plastic sealing composition,e.g. polyurethane coating 25, between the oblique web portions 5, whichafter its hardening forms a reliable seal which is not exposed tofatigue phenomena. Further sealing measures for the frame structure assuch are unnecessary at any other location.

FIGS. 8 to 10 show the fastening of the edges of the bearing structuresformed by the bolting together of the frames. To this end, a profiledsection 27 corresponding to the frame profile is fastened to the framesides adjacent to the wall of the room 26 by bolting, the profiledsection 27 appropriately extending over the entire width of the room.According to FIG. 8, the wall 26 of the room has a right-angled rail 39anchored into wall 26 by concrete. On the free extremity of rail 39 thehorizontal web portion 4 of the profiled section 27 is bolted with theinterposition of a seal. According to FIG. 9, the horizontal web orflange portion 4 of the profiled section 27 may also be anchored inconcrete directly into the wall 26 of the room. According to FIG. 10,the anchoring rail 39 comprises a simple straight rail. In the framesadjacent the wall of the room, clamping elements 15 and 16 areone-sided, as apparent from FIGS. 8 to 10. At the other extremity of thespindle 17 from that carrying the cap nut 18, this spindle has a nutmeans of a pin, so that after the pin has been driven out, unthreaded ofthe spindle from the bushing 31 is made possible. I

An advantage of the embodiment according to the invention is that it ismerely necessary to join the vertical middle web portions of twoadjacent frames by means of screws, thereby forming a box-likerectangular lower cavity wherein the clamping elements with theiroperating parts are rotatably inserted during the assembling operation.The filter ceiling completed in this manner need merely be suspendedfrom the bearer and suspension devices inset into the ceiling, which maybe performed in a simple manner by means of a bolt which is to beinserted through the vertical upper web portions of two adjacentprofiles and secured, which is rotatably journalled in double polyamidesleeves and located by nuts and split pins.

The embodiments according to the invention makes it possible toaccommodate filters of different thicknesses in one and the sameframe.Of importance is the possibility of application of a castableself-curing and permanently plastic sealing composition, which issqueezed in between the upper web portions after the individual profileframes have been assembled, concomitantly sealing off a triangularnarrow gap present between the vertical middle web portions. This jointis not exposed to any compressive stresses, so that fatigue phenomenacannot occur, thereby assuring permanent retention of the sealingaction. A contact between steel and aluminium is prevented, or thechipping-off of aluminium particles is prevented, by the inventivelyincorporated nylon bushings, during the rotation of the screwbolts foractuation of the clamping elements.

The present structure has been described in the context of a ceilingfilter. Thus, the terms upper and lower refer to the structure in thatcontext. There is no reason, however to limit the invention to the usein a ceiling since embodiments can be used for walls, etc.

I claim:

1. A structure for the support of air filters, comprising: adjacentsupport frames interconnected together; profiled sections substantiallyS-shaped in cross-section defining each said frame; pairs of saidadjacent sections together defining a hollow box-like portion; each saidsection having an upstanding web, an upper horizontal 40 (FlG.4)threaded on it, advantageously lockable by web extending inwardly ofeach frame, a downwardly directed oblique web extending from saidhorizontal web, a middle vertical web extending downwardly from saidoblique web, a horizontal flange extending inwardly of each frame fromsaid vertical web, a lower vertical web extending downwardly from saidhorizontal flange, an intermediate horizontal flange and a lowerhorizontal flange on said lower vertical web each extending outwardly ofeach said frame; each of said upstanding webs having a bore therein forthe accommodation of suspension means for each said frame; each of saidmiddle vertical webs having a bore therein; means interconnecting saidadjacent sections together extending through adjacent ones of saidmiddle vertical web bores; said intermediate and lower flanges eachhaving semi-circular recesses at their respective free ends; areleasable clamping and locking means defined by a rotatably mountedthreaded spindle disposed within the hollow box-like portion receivedwithin said semi-circular recesses of said horizontal flanges of saidadjacent sections; a clamping element on each said spindle for clampingan air filter panel within each said frame between each said clampingelement and said upper horizontal web; each said clamping element beinglocated on each said spindle for movement toward and away from saidhorizontal webs upon rotation of its spindle.

2. The structure according to claim 1 further comprising a cap nutengaged with the lower end of each said threaded spindle which extendsdownwardly beyond said lower horizontal flanges; the upper end of eachsaid spindle extending upwardly above said intermediate flanges; and athreaded nut in engagement with said upper end of each said spindle.

3. The structure according to claim 2 wherein nylon bushes are providedon each said spindle in engagement with said semi-circular recesses.

4. The structure according to claim 3 further comprising sealing meansprovided between said oblique webs of said adjacent sections.

5. The structure according to claim 4 wherein an end one of said framesis capable of being interconnected with a side wall by means of ananchor rail element interconnected with said upper horizontal web of anouter section of said hollow box-like portion.

II t t

1. A structure for the support of air filters, comprising: adjacentsupport frames interconnected together; profiled sections substantiallyS-shaped in cross-section defining each said frame; pairs of saidadjacent sections together defining a hollow box-like portion; each saidsection having an upstanding web, an upper horizontal web extendinginwardly of each frame, a downwardly directed oblique web extending fromsaid horizontal web, a middle vertical web extending downwardly fromsaid oblique web, a horizontal flange extending inwardly of each framefrom said vertical web, a lower vertical web extending downwardly fromsaid horizontal flange, an intermediate horizontal flange and a lowerhorizontal flange on said lower vertical web each extending outwardly ofeach said frame; each of said upstanding webs having a bore therein forthe accommodation of suspension means for each said frame; each of saidmiddle vertical webs having a bore therein; means interconnecting saidadjacent sections together extending through adjacent ones of saidmiddle vertical web bores; said intermediate and lower flanges eachhaving semicircular recesses at their respective free ends; a releasableclamping and locking means defined by a rotatably mounted threadedspindle disposed within the hollow box-like portion received within saidsemi-circular recesses of said horizontal flanges of said adjacentsections; a clamping element on each said spindle for clamping an airfilter panel within each said frame between each said clamping elementand said upper horizontal web; each said clamping element being locatedon each said spindle for movement toward and away from said horizontalwebs upon rotation of its spindle.
 2. The structure according to claim 1further comprising a cap nut engaged with the lower end of each saidthreaded spindle which extends downwardly beyond said lower horizontalflanges; the upper end of each said spindle extending upwardly abovesaid intermediate flanges; and a threaded nut in engagement with saidupper end of each said spindle.
 3. The structure according to claim 2wherein nylon bushes are provided on each said spindle in engagementwith said semi-circular recesses.
 4. The structure according to claim 3further comprising sealing means provided between said oblique webs ofsaid adjacent sections.
 5. The structure accoRding to claim 4 wherein anend one of said frames is capable of being interconnected with a sidewall by means of an anchor rail element interconnected with said upperhorizontal web of an outer section of said hollow box-like portion.